fix(nix,nvim): drop nodePackages.* (removed from nixpkgs), drop github-copilot-cli (broken)

nodePackages was removed wholesale from nixpkgs; everything that lived
under it must be referenced via its top-level name or dropped.

- prettier: moved nodePackages.prettier -> prettier (top-level alias).
- jsonlint: not available at top level. Dropped from nix/common.nix
  AND from the nvim-lint and conform-nvim configs in
  dot_config/nvim/lua/plugins/lsp.lua. jsonls already provides
  schema-aware diagnostics; jq still handles formatting. The
  jsonlint redundancy is acceptable to lose.
- github-copilot-cli (1.0.40 in nixpkgs): buildNpmPackage derivation
  doesn't redirect HOME during npm postinstall, so it fails with
  EACCES on /var/empty/.cache on Determinate nix. Removed; install
  manually from https://github.com/github/copilot-cli into
  /usr/local/bin/ as before (current host already has it there).

2 files changed, 7 insertions, 5 deletions

diff --git a/dot_config/nvim/lua/plugins/lsp.lua b/dot_config/nvim/lua/plugins/lsp.lua
index 98f0f66..51c8a2d 100644
--- a/dot_config/nvim/lua/plugins/lsp.lua
+++ b/dot_config/nvim/lua/plugins/lsp.lua
@@ -160,7 +160,7 @@ require("conform").setup({
     html = { "prettier" },
     javascript = { "prettier" },
     typescript = { "prettier" },
-    json = { "jq", "jsonlint" },
+    json = { "jq" },
     jsonc = { "prettier" },
     just = { "just" },
     markdown = { "mdformat" },
@@ -191,7 +191,6 @@ local lint = require("lint")
 lint.linters_by_ft = {
   css = { "stylelint" },
   dockerfile = { "hadolint" },
-  json = { "jsonlint" },
   markdown = { "markdownlint" },
   makefile = { "checkmake" },
   yaml = { "yamllint", "yq" },
diff --git a/nix/common.nix b/nix/common.nix
index 55e2d21..217d335 100644
--- a/nix/common.nix
+++ b/nix/common.nix
@@ -128,7 +128,11 @@ in
 
     # AI coding agents
     claude-code
-    github-copilot-cli # NB: pkgs.copilot-cli is AWS Copilot, NOT this
+    # github-copilot-cli intentionally not here: nixpkgs derivation (as
+    # of 1.0.40) fails to build on Determinate nix with EACCES on
+    # /var/empty/.cache (HOME not redirected during npm postinstall).
+    # Install manually from https://github.com/github/copilot-cli into
+    # /usr/local/bin/ instead.
 
     # ── LSPs / formatters / linters / DAPs ─────────────────────────────────
     # Replaces Mason entirely (phase p6 of the nix migration rips out
@@ -158,14 +162,13 @@ in
 
     # Formatters
     mdformat
-    nodePackages.prettier
+    prettier
     shfmt
     stylua
 
     # Linters
     codespell
     hadolint
-    nodePackages.jsonlint
     markdownlint-cli
     selene
     shellcheck